In excited preparation for Doctor Strange and the Multiverse of Madness, you decide to buy a blu ray copy of each of the

[answerhappygod]

In excited preparation for Doctor Strange and the Multiverse of
Madness, you decide to buy a blu ray copy of each of the Marvel
Cinematic Universe movies that are currently available for
purchase; there are 27 such films. Assume that you have 4 shelves
on which to place these blu rays, and that each shelf could, if you
so chose, hold all 27 blu rays. (a) How many ways could you arrange
the blu ray discs on a single shelf? Explain your reasoning. (b)
You ask your roommate to place the discs on the shelves. How many
ways could your roommate accomplish this task? Please explain your
answer. (c) Suppose that you insist that every shelf has at least
one disc. How many ways could you put the discs on the shelves?
Justify your answer.